First Measurements of the Sorption of Difluoromethane and Pentafluoroethane in Encapsulated Ionic Liquids

With millions of kilograms of refrigerants used in cooling applications today and legislation phasing out 85% of high global warming potential refrigerants over the next 15 years, there is a need for technology that ensures that these refrigerants can be reused and recycled rather than vented and incinerated. Because of the complex, often azeotropic, mixtures used as refrigerants today the gases must be separated in order to effectively be recycled. Ionic liquids have shown promise as entrainers in extractive distillation for the separation of azeotropic refrigerant mixtures. Encapsulated ionic liquids are an emerging technology that utilize the properties of the ionic liquid while giving them the functionality of being treated as a solid. This work will discuss the potential of encapsulated ionic liquids for these separations and present the first measurements of the sorption of difluoromethane and pentafluoroethane in encapsulated ionic liquids. This study found that the encapsulated ionic liquids' solubility is dominated by the ionic liquid while the diffusion is dominated by the polyurea shell.